This application relates generally to bar-code scanners such as those used in connection with point-of-sale (POS) terminals wherein coded retail item are presented to the scanner along a counter, the scanner automatically reads the bar code and communicates the retail item information to the POS terminal for transacting the sale of the item, inventory control, pricing, accounting, receipting, etc. More particularly, the invention concerns such a scanner that is miniaturized to produce a small, lightweight, low-cost, self-contained scanner the head of which is rotatably articuable and which can be mounted virtually anywhere and in any orientation.
Prior art POS terminal-connected mounted scanners require a large amount of retail outlet counter space and are relatively high-cost. Smaller scanners typically have relatively shallow and narrow viewing angles, or ranges, and thus are provided with extendable, retractable features, e.g. articuable, multiple arms enabling them to be extended and retracted for positioning adjacent a retail article. Of course, such require much manipulation by the retail sales associate and thus are inconvenient to use, as the scanners' heads must be constantly, or at least periodically, repositioned. Moreover, such scanners have been rendered smaller by removing much of the scanning electronics to a separate housing that requires under-counter space, which is at a premium. Essentially, the oversize problem is merely moved to another location, rather than being addressed and resolved. Known scan heads also have a larger volume than the scan head of the invention, which contributes to the lack of mounting flexibility in such scan heads.
There is a growing need for smaller, lighter weight bar-code rotatably articuable scanners that are versatile and inexpensive for use by retailers. There is also a growing need for rotatably articuable scanners that provide high performance, easily reachable scanning area that read bar codes quickly and accurately when retail articles are presented, with their bar codes generally facing the scanner, in a natural presentation or arc-sweeping motion by the retail sales associate. There is a growing need for rotatably articuable scanners that accommodate the variety of retail counter layouts of numerous retail outlets, and are interface-compatible with the variety of POS terminals that may be found therein.
Accordingly, it is a principal object of the invention to provide a highly functional rotatably articuable scanner that is extremely compact, yet extremely versatile in terms of compatibility with existing POS terminal interfaces and retail counter configurations.
Another important object of the invention is to provide such scanners that are capable of reading a bar code from an article independent of the axial orientation of the bar code relative to the scanner, and requiring only that the bar code be within a defined field of view of the scanner.
It is also a principal object of the invention to provide such a rotatably articuable scanners having improved viewing angles and depths to achieve higher scanning accuracy and reliability.
It is another important object of the invention to provide such scanners in an easily and quickly adjustable orientation to accommodate the idiosyncracies of various retail counter configurations and checker preferences.
It is also a principal object of the invention to provide such a rotatably articuable scanners at extremely low cost of manufacture and field maintenance.
Yet another object of the invention is to meet the above objectives in a scanner that is unimposing and attractive.
Recent advances in bar code scanners have made it possible to scan bar codes generally independent of the axial orientation of the bar code relative to the read axis of the scanner. The so-called asterisk scan pattern, consisting of plural lines crossing generally at their centers with their endpoints being spaced apart in a generally circular arc, can be used to read conventional linear bar codes used in retailing, without concern for the orientation of the surface of the bar code about the axis of the asterisk scan pattern, because at least one of the lines of the pattern will extend thereacross. One such bar code scanner producing an asterisk scan pattern is described in U.S. Pat. No. 4,939,356 issued Jul. 3, 1990 to Rando, et al., entitled BAR CODE SCANNER WITH ASTERISK SCAN PATTERN (which patent is commonly assigned with the present application) the disclosure of which is incorporated herein by this reference.
Another important, relatively recent advance in bar code scanners is the use of the so-called "basket" reflecting mirrors arrangement in which a frusto-conical array of fixed planar mirrors is disposed circumferentially around a centrally located rotating mirror, wherein the basket mirrors and rotating mirror operatively are associated with a laser preferably disposed within a tubular member collinear with the axis on which the central mirror rotates to produce a variety of scan patterns including such an asterisk scan pattern. One such basket-type scanner useful in producing an asterisk scan pattern is described in U.S. Pat. No. 4,699,447 issued Oct. 13, 1987 to Howard, entitled OPTICAL BEAM SCANNER WITH ROTATING MIRROR (Reexamination Certificate B1 U.S. Pat. No. 4,699,447, dated Jul. 3, 1990) (which patent is commonly assigned with the present application) the disclosure of which also is incorporated herein by this reference.
Briefly summarizing the invention, an extremely compact, lightweight, low-cost, self-contained, visible laser diode (VLD) printed bar code scanner is provided with a great range of adjustability and versatility. Preferably, a scan head housing the optical subsystem is fixedly rotatably connected with a tower housing the heat-generating electronic components of the scanner. The scan head housing contains a spin motor control, reflected light pattern detector, while the tower housing contains a bar code decoder and communication means, connectable with a conventional POS terminal via a multiple physical/electrical interface bulkhead located in a base for the tower housing. The scanner presents an extremely small footprint, and provides for its mounting in virtually any orientation and location. The scanner of the invention provide for hands-free scanning and one-handed adjustability.
Preferably, the optical subsystem uses a basket-type dispersal/collecting mirror array configured around a rotating planar folding mirror driven by an extremely compact cup (brushed) DC motor. Most of the optical components within the laser beam's path, as well as most of the mounting structures and housing components may be rendered in injection molded plastic to reduce weight and cost. The organization of components within the scan head and tower housings, as well as the partitioning thereof between the two, provides for convection cooled operation of the optical subsystem and rotation of the scan head, which has a center of mass near the scan head's axis of rotation, thereby making the scanner extremely stable despite its small footprint. Ease of depot and field maintenance and calibration of the optical subsystem is very simple because the replaceable components and subsystems may be easily removed and replaced without the need for realignment of the optical system. The scan head may be easily removed from the tower housing for convenience of maintenance and repair.
Unprecedented functionality and versatility in an ultra-compact bar code scanner is achieved by minimizing the length of the optical beam path, reducing component size, partitioning the optical subsystem from the associated electronics and choosing, configuring and mounting components of both for optimal compactness in an easily assembled, maintained and operated form.
These and other objects attained, and advantages offered, by the present invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawings.